Violating the accepted norms of social behavior
A social Psychologist with a PhD from Harvard, 1979, now a professor at Univ. Cali. Santa Barbara, formerly of Univ. Virginia on Trump's lying as compared with lying norms in the general population:
"By telling so many lies, and so many that are mean-spirited, Trump is violating some of the most fundamental norms of human social interaction and human decency. Many of the rest of us, in turn, have abandoned a norm of our own — we no longer give Trump the benefit of the doubt that we usually give so readily."
Commentary: I study liars. I've never seen one like Donald Trump.